1. Field of the Invention
The present invention relates to a process for removing caffeine from raw coffee. More specifically, the present invention relates to a process wherein raw coffee is contacted with an aqueous liquid to extract the caffeine therefrom and the resulting liquid is contacted with an adsorption agent that has been pre-loaded with at least one substance present in and extractable from the coffee or with a substitute therefor having a corresponding molecular structure and size.
2. Description of the Prior Art
It is known in the art that caffeine may be removed from raw coffee by various techniques. However, such known techniques generally present substantial disadvantages which detract from their use. For example, in practically all well-known processes for decaffeinating raw coffee used today, the coffee is extracted using organic solvents. A main disadvantage of this process resides in the fact that at least a trace of the solvent remains in the treated coffee. This residuum may adversely affect the taste and/or aroma of the brewed coffee product thereby decreasing its palatability.
In order to avoid the use of organic solvents, it is also known to extract the raw coffee with an aqueous liquid, to remove the caffeine from the extract solution by adsorption on an adsorption agent and subsequently to combine the remaining extract substances with the coffee beans. The disadvantage of the well-known processes of this type is that the adsorption agent, more particularly activated charcoal, adsorbs considerable quantities of other substances in the coffee besides the caffeine which thereby are lost and thus results in a product having a lower extract content.
The search has therefore continued for a process which will effectively remove caffeine from raw coffee without imparting an undesirable taste and/or aroma to the final product or substantially lessen the extract content. This invention is the result of that search.